of mikdletown



Feb. 21, 1928.

J. B. TYTUS PROCESS OF ROLLING SHEETS Original Filed March 12. 1923 A TTORNEYS Reiseued Feb. 21,1928. I

UNITED STATES JOHN 3.

"PATENT OFFICE,

/ v TUB, OI IIDDLETOWN, OHIO, ASSIGNOR TO THE AMERICAN ROLLING 001mm, HIDDLETOWN, OHIOQA CORPORATION 01' OHIO.

rnocnss or nonnnm snare. g

ori inal Io. 1,002,460, dated October 12,1920, cerium. 024,032," filed-larch is, was. Application mrellne fled January 4, 1998. Serial No. 244,540.

My invention relatestothe continuous rolling of metal, more particularly packs of metal sheets or doubled sheets, to finished gau and by continuous ,I mean that the pac or doubles are assed from one set of rolls to another to e ect successive reductions' thereon, in which each set of rolls is used but once on each pack. Two or-more strands will satisfy this definition,

There have been in the past a large number of theoretical sug estions for the rolling of sheet metal to fimslxed gauge by a continuous process. In a few instances continuous mills, so called, although-some would have been better classed as tandem mills, have been built and used in sheet rolling. So far as I'm advised with these mills, it

was always the practise to finish the packs r ordoubles, from the continuous process, in

a single stand of finishin rolls, according to the- Welsh system of re ling.

Thus my invention, which has the avowed object of finishing sheets to ultimate auge.

' in a continuous process, has a basis WhlCh is distinct from an ractical or even theoretical structure 0 t e past, in that it deals contour and predetermined temperature will with the problem of .reduction of thin, wide metal by sin le passes through successive stands of rol s in such a way as to solve the problem of control which has heretofore been'a stumbling block in attempts at continuous rolling, where the piece, were it a pack or a single thickness, had become so thin and wide that known methods of con-- trol failed to produce a satisfactory prod? not with anything approaching a. practical commercial re larity.

The discussion of the Welsh system of rollin will not require re-statement in this speci cation, as it is known at the present time, wherever steel sheets are rolled down from sheet bars. The si ificant reason'to which has been ascribed t e necessity of finishin sheets to final gau e on a single stand or ro ls, is. that the re er can watch the piece as it is being worked upon, and control-his roll draft accordingly to suit each articular piece and that t e piece having 11 given preliminary reduction one single stand of rolls thus acquires a fit to such peculiar variations in contour as the said stand of rolls While the 9, ve reasons mayor may not be entirely correct, it is quite significant ofthe many costly ejperiments of the past that economy in pr uction arising from the elimination of extra labor, which follows necessarily from a continuous process, has

always been more than overcome by the increase in wasters or ruined pieces, and in roll breakage, and shut downs.

It is the specific object of my invention to so design and control a rolling process, as to accomplish in a mechanical manner the work which a skilled roller would do in finishing a pack on a single stand of two hi h rolls. v I

o vthis end I take into consideration the following features which enter into any sheet rolling method (1 The prepared contour of the rolls.

E2 The temperature of the rolls. a

3 the rolls.

The composition and springiness of 4; The s acing of the rolls, or screw.

5 ture of the piece.

My ultimate aim is to so control these five factors, that a piece of a predetermined he engaged in each standof a'series of pairs of rol piece, wherein the rolls have a redetermined contour to fit the piece, sai being the resultant'of the five points above mentioned. I

. The rolls need not necessarily be repeated passes in a single stand of rolls.

While m process is primaril directed toward re action of hot metal, do not wish 'to' limit in self tohot metal alone as the metal may other than hot when .rolled.

To state the matter in another way, if a piece of material of given thickness is caused to pass through a pair of rolls, which are driven so as topull the piece along and attenuate or reduce it, the resultant shapeof 8, arranged to successively engage the roll contour The s ape, composition and temperaeneral, it is the rolliengagement dependvv part away from each other,

the. prepared sha such expansion as-t'o change this prepared contour. It will depend upon how far the journals of the rolls are rmitted to. space us to the position of the scr'ew,; which forms a stop for at lfiast one of the -rolls. It will depend upon the shape and condition of the piece and how resilient the rolls are when at the temperaturean'd under the. resultant pressures in question.

When a piece is engaged by the rolls, the rolls will spring at the center, if the piece is thicker than the s acingpermitted between the rolls because t e journals-at the ends of the rolls are the point'sfwhere the spacing limits are applied. Y v y w thgf'rolls have been nally on a slight concavity, this concavity the rolls afiect the ternaltreatment o areusually employed as controlling ,means is usually taken u ot, is more quickl dissi ated at the ends of the roll, with t e res t of a pufling out of the center thereof. The composition and condition of pufling tendenc and exthe rolls 'an' journals in the temperature, shape factor thereof.

The aha of the piece to start with, has also a decidingefiect upon the contour of the active. pass or space between the rolls,

,whilethe piece is between .them, particularl when the piece is thin, as a convex piece wi l naturally tend to afiect the spring of the rolls in a difierent way from a truly rectangular iece. f

It ould be noted that in speaking of contour of a pack of sheets, a sheet bar, on whatever piece is concerned, I am not referring to any shape whichwould be -apparent to thee e, as straight ineto the active pass or space between the rolls while a piece is between them, is not apparent to the eye. The contour or active pass is quite apparent, however, by

the variations over a true the examination of the piece, for at the point where the space between the rolls is less than at another, there. will be a greater extension of the piece.

. My method of successive or continuous that inthe tandem mill the from one set of rolls before it s engaged by another, and in the continuous mill the piece s gag y at lea t two of the stands atrolling olperates best in a set of rolls so arranged t at the iece is in only one stand at a time, and, w ile I have no knowledge which, willnecessarily eliminate the use of, the continuous mill, I prefer to use a'tandem other arrangement. The distinction be tween a continuous mill and a tandem mill is .thatwhile each has a succession of rolls, iece emerges u n of the rolls, and- Q tli: temperature thereo which has caused by the heating of-Jthe poll. The heat to t e rollslas applied by the piece itself,"which is often red iaaaa one time. Other arrangements of" stands of rolls would'be to stagger them or arrange them side by side.

Y .It should be noted that in referring to a continuous rolling process I do not confine myself to any type of inill but refer to the progression of the piece through a series of stands or rolls, in any arrangement.

In the continuous mill the error which may enter into the rolling in one stand, may accumulate or increase in the second stand without a chance of clirrecting it, and arthe continuous-mill requires a elicacy o adjustment of roll speeds which. is

a roblem that adds great additional difli-, cu tyto the design .of the mill. This last is p longer as it emerges the first mill .Wlll demand a greater speed in .the second mill to move the piece because the piece being a bug without an accumulation between the two stands. My process is applicable, however, to the continuous mill.

By referring to sheets, I do not desire to .be construed as relying upon any one of the current technical efinitions between sheets and plates, and between sheets and strips,

Q as the demarcation which I desire to make, is

thereof with hot rolled strips. Thus a hot rolled sheet or thin plate in the terminology of theart refers to a piece which because of exigencies of process can not be made in a long continuous bo'd mainly because of the relativewidth to thickness thereof, whereas a hot rolled strip is a piece which from exigencies of process has distinct limitations in width and thickness, but no limitations asto' length. The productswhich I make and to which I. refer fall into the first of these classes, so far as width and thickness, or

'gauge of the final roduct is concerned, my

its

problem being to so ve the matter of roll control where the metal has become so thin, and

at the same time so wide, that the :rule of thumb methodsof the past have failed, to produce it continuously.

It is thesesence 'ofm'y process, that-I rovide by the regulation of the elements a ve discussed for the production of a piece in eachstand of rolls which has a convex contour which is slightly more convex than the resultant active pass of the next stand of rolls, considering each active pass in the series "as a resultant of the factors outlined.

Thus the preferred manner in. which I I both rolls of each ture of the piece, preferably,

' may 80 convex in cross section,

to operate 85 tice'outlined by me, gain a throug the stand without changin usual expedients' for provide am'echanism for my process consists and their physica structure, and cutting their surfaces with screw and tem rature, thickness and contour of. piece will them. I control the temperature of therollsv by external means, and control the temperaheiiiters between the stands of" rolls. h u

n.-carrym" g out my rocess to re er mustkee in mind the fi 'e'factors rec ted, and use t em, in the manner with which he will be familiar, in conjunction with each other, to arrange the active pass in each stand-of rolls. Thus, if he finds the rolls will not run hollow enough, e if the active is too convex in outline, it may be that are und with too little concavity 'n wit and should be reground, it

that he should blow. air or pass wateronto the centers of the rolls, it ma be i m to.

-" that the rolls are not springy enough in t eir composition, it may be that his piece is too hot, or improper screw with relationto heat of the iece'has been applied. Then again the d' culty may be that the piece is too or not convex enough, the latter being the most probable. The skilled'roller knows how to control these factors recited, if he knows the effect to be gained, although of course, the usual skilled 35 roller would not be familiar with the bearof the several factors on each other, a ong the theoretical lines set forth in this specification.

A t ical instance in the rollin mill-as roller is given a test piece which he knows will have a convexity alike to the pieces he is to handle on a given run. He will pass thispiece through stand after-stand of 4B the rolls, and lplace a gauge upon its edges f the (passes are very bad,of not be used, as he will and middle.

course, the gauge nee know there is something wrong and can see with the eye that he is drawing the edges 60. or middle out too long thereby curling up or buckling the piece.

Having run the test piece or several test pieces, he will by his gauge, or by his eye .when he grows skilled in the new pracsetting of his rolls which providesan active pass in each stand which is less convex than the piece delivered to it-from the receding stands. Havin set his rolls, he W1 1 start the packs them further except in case of trouble w en he will again check up by gauge or by eye for progressively lessconvexlty of active ass.

He will naturally be provided with the control of heat on the a concavity, in one or pair, which at a given.

give a resultant convexity I of active pass when the piece is between furnaces or by me will be as fol ows:A'

' it enters and of gettin iece and rolls, control of screw and with owledge of the starting contour of the 'Ed e .1423,-

Mi dle .1965 Mi dle .1491.

After second pass, After third pass. Edge .1146 Ed .096 Middle .1201 Mi dle .1005

The active passes are all convex, although the'last one shows ve little difference be tween edges and middle. Also it would be possible and practical to vary from the exact figures given above in treatment of the given piece to gain the given final gauge. In practice the final 'gau e is' a fixed requirement on any one or er, as is the arrangement of the active passin each stand to reduce the middlemore than the edges and still preserve some convexit course, the maximum number o fixed quantity.

Given the starting convexity of'the pack, the number of active passes, and the final gauge to be rolled, the operators can readlly calculate a similar table to the above although as I have stated an absolute and mathematically exact correspondence to the example given, in the several active passes, is by no means required. ;.In the above I have referred to the ap licationof my invention to the rollin 0 packs, and it will be understood that tiis is given as an example, and that my novel discoveries are not limited in their ap lication to rolling of multiple thicknesses oi metal.

I should also observe,that due to the fact that'when the convexities have been rovided for properly, which the skilled ro ler can do readily if he regards the five factors which I have given above, and will further speak of, it will be found that the pack as asses each stand will lie smooth and feed accurately through the center of the roll stands. Thus it might readily be possible that the skilled roller could in a given instance working merely to the end a smooth pass, control 0 his roll bite in individual stands, but it would be next to impossible for him, without knowledge of the necessity of control of the five factors I have given, and the rule of convexity reduction, (i. e. greater reduction of-thicker than thinner parts of the piece) for him to handle allof the stands by rule of thumb, or to adjust the stands for different sizes, drafts, kinds of metal,

Also, of passes is a passes through three stands;

hit upon a proper It is pre erable to watch close 'the s ring in t I use as many stands of rolls as the desired reduction requires, and furnish to the first stand of the rolls a piece which has been formed with the desired contour to start with. a I

The thicker the piece is at the start the more readily will it take the contour which is desired without 'bad results, and if for example I provide a. pack or doubled-1gp body of thin plates accordinglto the We stem, this pack will natura cided convent of contour, resulting from he rolls which formed the indivi ual lates from which the ack is made.

the formation of the plates from whicht e packs are formed so that the starting contour is exactly right, although as stated, the thickness of the piece makes errors one way or the other of not so much importance at the I exaggerat sheets start.

In the drawings Figure 1 is a side elevation of three-tandem rolls in diagram with an exaggoir'ated illustration of three pieces passing theFrolls. 1 d J f i re 2 is a ion iagram exag ated t d illustrate-the pass through the ist stand. 1

Fi re 3 is a hke view for the second stan ,and

Figure 4 for the third stand. 7

I have illustrated in diagram three sets of rolls (two high), at 1, 2 and 3' althou h it will be understood that more stands. co d be added. The piece is illustrated at 1, 2 and 3'. In section in Figure 2 is shown the'progressive convexity of the piece, durin its reduction. The convexity is, as has said, not a parent to the eye and has been ed The piece may be a pack of or a single plate to begin with. The

space between e rolls is defined by the knee 1", 2" and 3", these 'lines illustrating, by the spiilge'betwe'en them, the active pass of the m v I will preferably start with a iece formed of lates. of the ty known as e bed plate,

or'ming of pac s, when applying my 1nplates may vention thereto. w These formed in a tandem milloperating according to my process, "if desired, and when trimmed and piled or doubled should be arranged so that the lengthwise components of the plates in a pack are-iniine with each other- Thus an crest or convexity on the plates will be a ded together to produce a pack of a curve of convexity avin a shorter diameter than that of any indivi ual plates maldng it up.

- The reasons forma'intaining the contour as I have stated are many, but it will suflice to point out, with a convexity slightly y have a demesa less than the convexity of the preceding pass there will be a tendency of the rolls m a pass in question to line up the piece with-the crest of convexityrunningethrough the crest of the convex active as tween the rolls.

Also, as the thic comes reduced and the amount of screw on the rolls, and hence pressure exerted in attenuating the piece, must be varied to efiect the desirable reduction, I have found that (385 of the piece beif the various elements going into the result 7 trolling the variable elements so that the true function of the special design of rolls, heating devices, and the like will operate to the end above outlined. The savin in the services of assistants is very greafii; 55 by waste pieces, and roll breakage will be very slight as compared to past attempts at accomplishinga continuous rolling1 process.

The term active-pass as used in t is specification refers to the space between rolls while the are in engagement. with the piece being rol ed therebeteween.

I do not desire my specification above to be construed as limitation to the claims that follow, wherein it is my desire that the full application of the doctrine of equivalents be' followed in their construction. Having thus described my invention, what claim as new and-desire to secure by Letters'Patent, is:-

1. A continuous process for reducin hot metal to sheet form in successive stan s of rolls. which consists in passing a piece of 'metal from one stand to another successively and controlling the active pass of the rolls in each stand so as to form for the next stand apiece of slightly ater convexity than the active pass of sai next stand.

2. A continuousrocess forv reducing hot metal to thin wide orm in successive stands of rolls which" consists in passin a I iece of metal through one stand of rol s a ter another successively and im ressing upon the piece b the active ass 0 the first and each succee ing stand 0 rolls, a cross sectional shape of other'than parallel surfaces, which will be made more nearly parallel surfaces in each active pass.

3. A continuous process for reducing hot ect the desired reduction will metal tosheet-like form which consists in I passing a iece of metal through one stand of rolls a r another successively, and proup I vidin an active pass in each stand of rolls, of

lfl'erent predetermined non-parallel sided contour;

4. A continuous process for reducing a ack or doubled mass of plate metal to sheet orm, in successive stands of rolls, which consists in passing a piece ofmetal from one stand to another successively and controlling the active pass of the rolls in each stand on said pack so as to deliver to the next stand a piece which has' a slightly greater convexlty than the active pass of said next stand.

.5. That process of reduction of metal to sheet form, which consists in forming a pack or doubled mass of plate metal, in which the arrangement is such that the line of feed of the ack will be a continuation of the line of feed in forming each plate thereof, and atsuitable temperature passing said pack thro h successive stands of finishing rolls, and in each stand controlling the active pass of the. rolls so as to produce a piece having a slightly less convex form/ thanwas the form livered to it.

process for reducing hot metal to sheet-like form which consists in passing a .piece of metal through one stand of rolls after another successively, and providing an active ass 'in each stand of rolls, of predetermine contour, said contour beingone which will cause the piece to pass through the middle of' each succeeding active pass, but the final contour being within the tolerance of accepted commercial variation as to uniformity of gauge and flatness.

7. A continuous process for reducing wide and thin metal to sheet form in successive stands of rolls, which consists in passing a piece of metal from one stand to another successively and controlling the active pass of the rolls in each stand so as to form for the next stand a piece of slight- 6. A continuous 1y greater convexity than the active pass 45 of said next stand.

JOHN B. TYTUS.

of the piece when de- 35 

